The use of balloons for military operations goes right back to the earliest days of flight. Although fixed wing aircraft quickly replaced them, balloons continued to have their uses and between 10 Jan and 6 Feb 1956 over 448 high-altitude balloons were launched towards Russia on photographic reconnaissance sorties in the GENTRIX programme.
These days balloons and other lighter-than-air systems are generally referred to as Aerostats and a number of companies manufacture aerostats equipped with radar and other surveillance systems. A permanently deployed aerostat surveillance system can provide a low-cost long-endurance capability not possible with a fixed wing aircraft. Many of the current helium filled aerostats can be deployed and operated by a crew of just 2 people. Lockheed Martin alone has delivered over 8,000 aerostats for military and commercial uses.
In Feb 04 Lockheed Martin were awarded a contract to provide two 56,000 cubic foot tethered aerostat surveillance systems for deployment in Iraq. The first aerostat will be delivered to Iraq in Jun 04, with the second system following a couple of months later. The aerostats will be deployed around Baghdad, assisting in the defence of ground forces and high value assets in that area. Once tethered into position at 1,000ft above ground, the aerostat will provide radar coverage out to 30kms and the electro-optical system will give coverage out to 10kms, as well as acting as a communications relay system for US forces. The electro-optical system can easily be supplemented by an infrared camera or replaced by an Electronic Support Measures (ESM) package or laser designator.
Although these aerostats are quite large, they are dwarfed by the aerostats Lockheed Martin has in place along the border between the US and Mexico. The Tethered Aerostat Radar System (TARS) is operated by the US Air Force and uses a series of 420,000 cubic foot balloons equipped with the Lockheed Martin L-88 radar in support of air sovereignty and counter-drug operations. The tethered balloons can be deployed up to 15,000ft and carry wither the AN/DPS-5 S-band or CFAR/MTI and AN/TPS-63 search radars.
Israel has also used aerostats for a number of years and RAFAEL are currently marketing their Stratus COMINT and surveillance system. Designed for coastal, air and ground surveillance gathering and as a communications relay, the Stratus is easy to deploy and can provide coverage for up to 30 days. Another Israeli company, IAI Elta are even proposing the separate deployment of a sensor platform originally designed for an Aerostat. The mast mounted sensor group can be fitted with various sensors including a colour CCD and a FLIR fitted with a x 1.4 magnification lens. A laser rangefinder/marker, an EL/M-2129 ground surveillance radar and electronic compass can also be installed.
Operated by a small crew with little need of much logistical support, a tethered aerostat can provide a considerable capability for relatively small cost. However, they cannot be launched in high winds, so must be backed up by other complimentary fixed wing systems. Nevertheless, these aerostat systems are being continually refined and improved and probably will soon be a common fixture wherever US Forces are deployed.